Container cap having safety lock means

ABSTRACT

A safety container-cap, particularly for bottles, wherein a stopper seat is permanently attached to the top of the bottle, and the stopper is flexibly hinged to the top of the stopper seat. In a preferred embodiment a slide channel extends diametrically through the stopper, and a pair of recesses are positioned within the stopper seat on diametrically opposite sides thereof and in alignment with the slide channel to receive a pin member which may be retracted to disengage the slide channel of the stopper or, when the stopper is closed, extends through the slide channel of the stopper and into the two recesses firmly holding the stopper in engagement with the stopper seat, thereby keeping the bottle closed.

United States Patent [191 Lemons Dec.9,1975

[ CONTAINER CAP HAVING SAFETY LOCK MEANS [75] Inventor: John B. Lemons, Clements, Calif.

[73] Assignee: Bob Mar, Stockton, Calif.

[22] Filed: Aug. 20, 1974 [21] App]. No.: 498,942

Related US. Application Data [63] Continuation of Ser. No. 358,008, June 7, 1973,

abandoned.

52 US. Cl. 215/213 [51] Int. Cl. B65D 51/12 [58] Field of Search 215/9, 210, 213

[56] References Cited UNITED STATES PATENTS 3,181,718 5/1965 Chancellor 215/213 3,623,622 11/1971 Sullivan 215/213 Primary Examiner-George T. Hall Attorney, Agent, or Firm-Townsend and Townsend [5 7] ABSTRACT A safety container-cap, particularly for bottles, wherein a stopper seat is permanently attached to the top of the bottle, and the stopper is flexibly hinged to the top of the stopper seat. In a preferred embodiment a slide channel extends diametrically through the stopper, and a pair of recesses are positioned within the stopper seat on diametrically opposite sides thereof and in alignment with the slide channel to receive a pin member which may be retracted to disengage the slide channel of the stopper or, when the stopper is closed, extends through the slide channel of the stopper and into the two recesses firmly holding the stopper in engagement with the stopper seat, thereby keeping the bottle closed.

38 Claims, 10 Drawing Figures 1 1 a 4 I l' g 20 'II;LIII l "'l 51111 I l i 15 l I Sheet 1 of 2 Dec. 9, 1975 U8. Patent Patent Dec. 9, 1975 Sheet2of2' 3,924,768

CONTAINER CAP HAVING SAFETY LOCK MEANS BACKGROUND OF THE INVENTION This is a Continuation of patent application, Ser. No. 358,008, filed June 7, 1973 by John B. Lemons for a CONTAINER CAP; now abandoned.

Various states and foreign governments require or will require that medicine bottles and bottles containing poisons and other damaging fluids must have safety caps which may not be opened by immature children. The caps are typically tested by placing them in the hands of children below the age of five years to determine how many of such children can open the cap within a half-hour, an hour, two hours, etc.

The cap must, however, be readily openable by an adult, and it is expected thatas the child matures he will also be able to open the cap. It is for this reason that one might characterize the cap laws as child resistant cap laws rather than child-proof cap laws.

Very few other bottle caps, if any, can meet the government requirements. The cap contemplated by this invention, however, has been thoroughly tested and is incapable of being opened by the required number of immature children.

BRIEF DESCRIPTION OF THE INVENTION The container cap contemplated by this invention is particularly useful for sealing medicine bottles, and the like. In the preferred embodiment it is substantially a three part cap, comprising a stopper seat which may be permanently attached to the bottle, a stopper which may be hinged to the stopper seat, for example, by a flexible hinge, and a pin member which is positioned and adapted to slide in the stopper from one recess on one side of the stopper seat, through a slide channel in the stopper, into a recess on the other diametrically opposed side of the stopper seat.

The pin and recesses, typically have stops to prevent the pin from failling out of the stopper seat and to prevent the pin from being pushed in too far, whereby it could not conveniently be withdrawn. Typically a tang is provided on the protruding end of the pin whereby one may grasp the tang with the finger nail to withdraw the pin from engagement with the slide channel in the stopper, thereby allowing the stopper to be removed from the stopper seat.

In alternative embodiments two or more slide channels, positioned along chords of the stopper, may be used. The channels need not be precisely positioned; they need not be parallel; they need not be on the same plane; they need not be equi-distant from the center of the stopper.

It is within the contemplation of this invention that two recesses be aligned within the stopper seat for each slide channel in the stopper to receive a pin from that slide channel. It is also contemplated that one of the recesses in each pair penetrate the side of the stopper seat for withdrawal of the pin from its respective slide channel. It is also contemplated that stops should be provided for each pin and that each pin should have a finger nail tang.

Instead of having two recesses within the stopper seat for each pin, it is within the contemplation of this invention that an annular channel should be provided on the inner surface of the stopper seat as a continuous recess.

It is therefore an object of this invention to provide a lock for a container cap.

It is a more specific object of this invention to provide a safety cap for containers.

BRIEF DESCRIPTION OF THE DRAWINGS Other objects will become apparent from the following description, taken in connection with the accompanying drawings, in which:

FIG. 1 is a top plan view of the stopper of this invention, in a preferred embodiment, with the position of the pin, in its withdrawn position, shown in dashed lines.

FIG. 2 is a side view of the cap of FIG. 1 with the stopper open and the locking pin fully disengaged.

FIG. 3 is a section view taken at 33 in FIG. 1.

FIG. 4 is a fragmentary, section view of the stopper, taken at 4-4 in FIG. 3.

FIG. 5 is a fragmentary view taken at 5-5 in FIG. 1.

FIG. 6 is a section view, with the pin in profile, taken at 66 in FIG. 3.

FIG. 7 shows diagramatically how two substantially 7 parallel slide channels may be positioned within and on two chords of a stopper.

FIG. 8 shows two non-parallel slide channels in and on two chords of a stopper.

FIG. 9 shows a stopper seat with a single annular recess.

FIG. 10 is a section view taken at 10-10 in FIG. 9.

DETAILED DESCRIPTION OF THE INVENTION With increasing safety consciousness on the part of the public, various state legislatures and the legislatures of foreign countries have passed laws requiring that the top of medicien bottles and bottles containing other harmful materials must be resistant to the immature child. The measure of the adequacy of the resistance is how long it takes a child to open the bottle. The bottle top contemplated by this invention is extremely resistant to opening by an immature child.

Referring to the figures, the container cap of this invention comprises a stopper seat 10, a stopper l2, and, in a preferred embodiment, one pin 14.

The stopper seat 10 has an inner cylindrical member 16 which is sized to fit inside the mouth 18 of a bottle. An outer skirt 20 has two annular grooves which form an interference fit with corresponding ridges 22, 24 on the outside of the bottle neck 18. The inner cylindrical member 16 is slightly flared inwardly at 26 to allow entrance of the stopper seat into the bottle neck 18. It should be noted that although the stopper seat is shown cylindrical in a cylindrical bottle neck, the seat and bottle neck may be shaped in other shapes. For example, the bottle neck and stopper seat could be slightly flared (not shown). The stopper seat 10 sits astride the top of the bottle neck 18 and, preferably, an annular lip seal 30 depends from the stopper seat 10, resting in a flexed and sealing position upon the top of the bottle neck 18 to seal the contents of the bottle. The technique of using ridge rings 20, 24 on the outside of the bottle in combination with annular grooves to hold on the stopper seat is only one of a number of structures that may be used. The shown structure has the advantage that it cannot readily be removed.

The stopper 12 is contoured to fit into the stopper seat 10. With a cylindrical seat, the stopper is cylindrical. The outer surface of the stopper l2 and the inner 3 surface of the stopper seat are complementary in a sliding fit at 40.

In the preferred embodiment of FIGS. 1-6, the stopper 12 has formed thereon a slide channel 42 which is substantially rectangular as shown more particularly in FIG. 4. The pin 14 is shown as having an I-I-shaped section With the bottom corners of the H sliding on the inner surface of the slide channel 42 at 46, 50. Clearance is provided at 44, 48 between the pin 14 and the top of the channel 42 to allow the stop 60 freely to clear the top of the channel 42. The cross section of the pin 14 is H-shaped, as shown in FIG. 4, except at its ends where it is substantially rectangular.

Preferably two diametrically opposed recesses 52, 54 shown more particularly in FIG. 6, are formed in the side walls of the stopper seat 10. The first recess 52 penetrates through the side wall of the stopper seat 10 while the recess 54 does not. It is not intended, however, that the concept of this invention should be avoided by allowing the recess 54 to penetrate the entire side wall of the stopper seat 10. The slide channel 42 of the stopper 12 is aligned with the recesses 52, 54 of the stopper seat 10.

The pin 14 has an upstanding stop 60 on one end thereof which is contoured to match the contour of the stop 62 on the stopper seat 10. The stop 62 partly blocks the slide channel 42 so that engagement of the upstanding stop 60 with the bridge 62 prevents the pin 14 from being pulled out of the recess 52. The stop 60, however, is positioned so that when it engages the bridge-stop 62, the pin 14 will be completely withdrawn from the channel 42.

The upstanding tang 64 has a two-fold purpose. When the pin 14 is pushed fully inward, the tang 64 abuts the stop surfaces 66, 68, preventing further penetration by the pin 14. The tang 64 is also adapted to be grasped by ones finger nail to pull the pin 14 out of the slide channel 42. The opening 70 in the stopper seat allows easy access to the tang 64.

FIG. 7 shows, diagramatically, two slide channels 80, 82 directed along chords of the stopper 12. The channels 80, 82 need not be coplanar nor equidistant from the center of the stopper 12.

FIG. 8 shows, diagramatically, two non-parallel slide channels 84, 86 directed along chords of the stopper 12. The channels 84, 86 need not be coplanar nor equidistant from the center of the stopper 12.

In each of the embodiments of FIGS. 7 and 8, a pair of recesses are formed in the stopper seat 10 (recesses not shown) aligned with the respective slide channels, and one of the recesses penetrates the side wall of the stopper seat 10 for each slide channel to receive a pin. The pin (now shown) is positioned in those slide channels in the same fashion as that shown in FIGS. 1-6.

Instead of having a recess on each end of the slide channel of FIGS. 1-6 or the channels of FIGS. 7 and 8, one could have a single recess formed around the periphery of the stopper seat as shown by the annulus 90 in the stopper seat 10 of FIGS. 9 and 10.

In operation, with the stopper 12 open as shown in FIG. 2, the pin 14 is completely disengaged from the stopper l2 and the stop 60 is typically against the bridge-stop 62. To lock the top closed, the stopper 12 is closed as shown in FIG. 3, and the pin 14 is pushed through the slide channel 42 into the recess 54. The tang 64 abuts against the surfaces 66, 68, preventing further penetration of the pin 14 into the recess 54. The top is now locked shut. To open the top, the finger nail 4 is placed into the opening and engaging the tang 64. The nail may then be used to pull the pin 14 out of engagement with the stopper 12, allowing the stopper 12 to be opened.

In the embodiments of FIGS. 7 and 8, two pins are used, .and must be operated, instead of one pin. Further, if desired, more pins and slide channels may be built into the apparatus.

Thus, the apparatus of this invention is a secure container cap which resists the attempts of immature children to open it, and it.is extremely valuable in meeting new safety requirements for medicine bottle caps, and the like.

Although the invention has been described in detail above, it is not intended that the invention should be limited by that description, but only by that description in combination with the description in the appended claims.

I claim:

1. A cap for a container comprising:

a stopper seat, sized to fit into the mouth of and to rest on the mouth of a container;

a stopper, sized to fit into and conform to said stopper seat, including at least one slide channel formed in and directed across said stopper;

at least one recess in said stopper seat, aligned with said slide channels; and

at least one pin, equal in number to said slide channels, each slidable in said recesses and one of said slide channels to lock said stopper into said seat.

2. A container cap as recited in claim 1 in which said recesses are formed in said stopper seat adjacent the ends of said slide channels to receive said pins, said recesses penetrating the wall of said stopper at at least one end of each said slide channel to form openings which are sized to allow said pins, respectively, to slide from said adjacent slide channel through said opening, and in which said pins are each sufficiently long to extend the length of said slide channels, respectively, between said recesses at opposite ends of said slide channels.

3. A container cap as recited in claim 2 in which said pins and said recesses have mutually engaging stops, positioned to prevent full extraction of said pins from said stopper seat while allowing full disengagement between said pins and said slide channels of said stopper.

4. An article of manufacture as recited in claim 3 in which said pins and said recesses each have a second pair of mutually engaging stops to oppose the entry of said pins into said recesses beyond predetermined positions.

5. An article as recited in claim 4 in which each said pin has a grasping tang on one end thereof, adapted to be grasped by the finger nail of a user to withdraw said pin from engagement with its said slide channel of said stopper.

6. An article as recited in claim 5 in which said tang I and the said stop of said second pair of stops, upon said pin are attached.

7. Apparatus as recited in claim 6 in which each said slide channel is substantially rectangular in section.

8. Apparatus as recited in claim 7 in which each said pin, except at its ends, is substantially H-shaped in section, the ends of said pin being substantially rectangularly shaped in section, the transition region of said pin between said H-shape section and said rectangular shape section on one end of said pin forming said grasping tang, and the transition region of said pin between said H-shape section and said rectangular shape section on the other end of said pin forming said first-named stop on said pin.

9. An article as recited in claim 5 in which said stopper is hinged to said stopper seat.

10. An article as recited in claim 9 in which said hinge is a flexible hinge.

11. An article as recited in claim 5 and further comprising a lip seal, positioned on and depending from said stopper seat to seal the top of a container to said stopper seat.

12. An article as recited in claim 11 in which said stopper seat further comprises a skirt depending therefrom and sized to engage the exterior of the mouth of a bottle.

13. Apparatus as recited in claim 12 in which said skirt has a pair of annular grooves formed in and encircling the interior thereof to engage corresponding ridges upon the exterior of the mouth of a bottle.

14. An article as recited in claim 13 in which said stopper is hinged by a flexible hinge to said stopper seat.

15. Apparatus as recited in claim 14 in which each said slide channel is substantially rectangular in section, and in which each said pin, except at its ends, is substantially I-I-shaped in section, the ends of said pin being substantially rectangularly shaped in section, the transition region of said pin between said I-I-shape section and said rectangular shape section on one end of said pin forming said grasping tang, and the transition region of said pin between said H-shape section and said rectangular shape section on the other end of said pin forming said first-named stop on said pin.

16. Apparatus as recited in claim 15 in which said stopper has only one slide channel, positioned substantially along the diameter of said stopper.

17. Apparatus as recited in claim 16 in which said recesses are formed in one continuous annular groove around the inside surface of said stopper seat.

18. Apparatus as recited in claim 15 in which said slide channels are on substantially parallel chords of said stopper.

19. Apparatus as recited in claim 15 in which said slide channels are on non-parallel chords of said stopper.

20. In a stopper seat and stopper combination, the improvement comprising:

means forming a channel through said stopper seat;

a pin, positioned within said channel; and

recess means on said stopper seat for engaging said pin to lock said stopper in closed position relative to said seat.

21. Apparatus as recited in claim 20 in which said improvement further comprises:

6 said pin from being pushed in beyond a predetermined position. 23. The improvement of claim 22 in which said tang is contoured and positioned to be engaged by a finger 5 nail.

24. In combination:

a container having a stopper seat;

a stopper, sizedto fit into and conform to said stopper seat, including at least one slide channel formed in said stopper;

at least one recess in said stopper seat, aligned with a slide channel; and

at least one pin, slidable in said recess and a slide channel to lock said stopper into said seat.

25. A combination as recited in claim 24 in which each said is formed in said stopper seat adjacent the end of the slide channel aligned therewith to receive said pin, said recess penetrating the wall of said stopper at at least one end of each said slide channel to form an opening which is sized to allow said pin, respectively, to slide from said adjacent slide channel through said opening, and in which said pin is sufficiently long to extend the length of said slide channel.

26. The combination of claim 25 in which said pins and said recesses have mutually engaging stops, positioned to prevent full extraction of said pins from said stopper seat while allowing full disengagement between said pins and said-slide channels of said stopper.

27. The combination of claim 26 in which said pins and said recesses each have a second pair of mutually engaging stops to oppose the entry of said pins into said recesses beyond predetermined positions.

28. The combination of claim 27 in which each said pin has a grasping tang on one end thereof, adapted to be grasped by the finger nail of a user to withdraw said pin from engagement with its said slide channel of said stopper.

29. The combination of claim 28 in which said tang and the said stop of said second pair of stops, upon said pin, are attached.

30. Apparatus as recited in claim 29 in which each said slide channel is substantially rectangular in section.

31. The combination of claim 30 in which each said pin, except at its end, is substantially H-shaped in section, the ends of said pin being substantially rectangularly shaped in section, the transition region of said pin between said H-shape section and said rectangular shape section on one end of said pin forming said grasping tang, and the transition region of said pin between said H-shape section and said rectangular shaped section on the other end of said pin forming said firstnamed stop on said pin.

32. The combination of claim 28 in which said stopsaid recess means being formed on opposing sides of per is hinged to said stopper seat.

said stopper seat and aligned with said channel; and said pin extending in length from said recess means on one side of said seat, through said channel, and into said recess means on the other side of said seat.

22. The improvement of claim 21 wherein said pin has a tang thereon which may be grasped to withdraw said pin from said channel, and including openings in said seat to allow such withdrawal; and

stops on said seat and said pin to prevent complete withdrawal of said pin from said seat while allowing said pin to be completely withdrawn from said channel, said stops further cooperating to prevent 33. An article as recited in claim 28 in which said hinge is a flexible hinge.

34. The combination of claim 24 in which said stopper seat has a skirt depending therefrom and sized to engage the exterior of the mouth of a bottle.

35. The combination of claim 34 in which said skirt has a pair of annular grooves formed in and encircling the interior thereof to engage corresponding ridges upon the exterior of the mouth of a bottle.

36. The combination of claim 24 in which said stopper seat is at the mouth of a bottle.

37. In combination:

a container having a stopper seat;

7 a stopper, sized to fit into and conform t aid stopone of said slide channels to lock said stopper into per seat, including at least one slide channel 531d Seat formed in and direct d a r aid t 38. The combination of claim 37 in WhlCh said pins at least one recess in said stopper seat, aligned with are equal number to sand recessessaid slide channels; and at least one pin, each slidable in said recesses and 

1. A cap for a container comprising: a stopper seat, sized to fit into the mouth of and to rest on the mouth of a container; a stopper, sized to fit into and conform to said stopper seat, including at least one slide channel formed in and directed across said stopper; at least one recess in said stopper seat, aligned with said slide channels; and at least one pin, equal in number to said slide channels, each slidable in said recesses and one of said slide channels to lock said stopper into said seat.
 2. A container cap as recited in claim 1 in which said recesses are formed in said stopper seat adjacent the ends of said slide channels to receive said pins, said recesses penetrating the wall of said stopper at at least one end of each said slide channel to form openings which are sized to allow said pins, respectively, to slide from said adjacent slide channel through said opening, and in which said pins are each sufficiently long to extend the length of said slide channels, respectively, between said recesses at opposite ends of said slide channels.
 3. A container cap as recited in claim 2 in which said pins and said recesses have mutually engaging stops, positioned to prevent full extraction of said pins from said stopper seat while allowing full disengagement between said pins and said slide channels of said stopper.
 4. An article of manufacture as recited in claim 3 in which said pins and said recesses each have a second pair of mutually engaging stops to oppose the entry of said pins into said recesses beyond predetermined positions.
 5. An article as recited in claim 4 in which each said pin has a grasping tang on one end thereof, adapted to be grasped by the finger nail of a user to withdraw said pin from engagement with its said slide channel of said stopper.
 6. An article as recited in claim 5 in which said tang and the said stop of said second pair of stops, upon said pin are attached.
 7. Apparatus as recited in claim 6 in which each said slide channel is substantially rectangular in section.
 8. Apparatus as recited in claim 7 in which each said pin, except at its ends, is substantially H-shaped in section, the ends of said pin being substantially rectangularly shaped in section, the transition region of said pin between said H-shape section and said rectangular shape section on one end of said pin forming said grasping tang, and the transition region of said pin between said H-shape section and said rectangular shape section on the other end of said pin forming said first-named stop on said pin.
 9. An article as recited in claim 5 in which said stopper is hinged to said stopper seat.
 10. An article as recited in claim 9 in which said hinge is a flexible hinge.
 11. An article as recited in claim 5 and further comprising a lip seal, positioned on and depending from said stopper seat to seal the top of a container to said stopper seat.
 12. An article as recited in claim 11 in which said stopper seat further comprises a skirt depending therefrom and sized to engage the exterior of the mouth of a bottle.
 13. Apparatus as recited in claim 12 in which said skirt has a pair of annular grooves formed in and encircling the interior thereof to engage corresponding ridges upon the exterior of the mouth of a bottle.
 14. An article as recited in claim 13 in which said stopper is hinged by a flexible hinge to said stopper seat.
 15. Apparatus as recited in claim 14 in which each said slide channel is substantially rectangular in section, and in which each said pin, except at its ends, is substantially H-shaped in section, the ends of said pin being substantially rectangularly shaped in section, the transition region of said pin between said H-shape section and said rectangular shape section on one end of said pin forming said grasping tang, and the transition region of said pin between said H-shape section and said rectangular shape section on the other end of said pin forming said first-named stop on said pin.
 16. Apparatus as recited in claim 15 in which said stopper has only one slide channel, positioned substantially along the diameter of said stopper.
 17. Apparatus as recited in claim 16 in which said recesses are formed in one continuous annular groove around the inside surface of said stopper seat.
 18. Apparatus as recited in claim 15 in which said slide channels are on substantially parallel chords of said stopper.
 19. Apparatus as recited in claim 15 in which said slide channels are on non-parallel chords of said stopper.
 20. In a stopper seat and stopper combination, the improvement comprising: means forming a channel through said stopper seat; a pin, positioned within said channel; and recess means on said stopper seat for engaging said pin to lock said stopper in closed position relative to said seat.
 21. Apparatus as recited in claim 20 in which said improvement further comprises: said recess means being formed on opposing sides of said stopper seat and aligned with said channel; and said pin extending in length from said recess means on one side of said seat, through said channel, and into said recess means on the other side of said seat.
 22. The improvement of claim 21 wherein said pin has a tang thereon which may be grasped to withdraw said pin from said channel, and including openings in said seat to allow such withdrawal; and stops on said seat and said pin to prevent complete withdrawal of said pin from said seat while allowing said pin to be completely withdrawn from said channel, said stops further cooperating to prevent said pin from being pushed in beyond a predetermined position.
 23. The improvement of claim 22 in which said tang is contoured and positioned to be engaged by a finger nail.
 24. In combination: a container having a stopper seat; a stopper, sized to fit into and conform to said stopper seat, including at least one slide channel formed in said stopper; at least one recess in said stopper seat, aligned with a slide channel; and at least one pin, slidable in said recess and a slide channel to lock said stopper into said seat.
 25. A combination as recited in claim 24 in which each said is formed in said stopper seat adjacent the end of the slide channel aligned therewith to receive said pin, said recess penetrating the wall of said stopper at at least one end of each said slide channel to form an opening which is sized to allow said pin, respectively, to slide from said adjacent slide channel through said opening, and in which said pin is sufficiently long to extend the length of said slide channel.
 26. The combination of claim 25 in which said pins and said recesses have mutually engaging stops, positioned to prevent full extraction of said pins from said stopper seat while allowing full disengagement between said pins and said slide channels of said stopper.
 27. The combination of claim 26 in which said pins and said recesses each have a second pair of mutually engaging stops to oppose the entry of said pins into said recesses beyond predetermined positions.
 28. The combination of claim 27 in which each said pin has a grasping tang on one end thereof, adapted to be grasped by the finger nail of a user to withdraw said pin from engagement with its said slide channel of said stopper.
 29. The combination of claim 28 in which said tang and the said stop of said second pair of stops, upon said pin, are attached.
 30. Apparatus as recited in claim 29 in which each said slide channel is substantially rectangular in section.
 31. The combination of claim 30 in which each said pin, except at its end, is substantially H-shaped in section, the ends of said pin being substantially rectangularly shaped in section, the transition region of said pin between said H-shape section and said rectangular shape section on one end of said pin forming said grasping tang, and the transition region of said pin between said H-shape section and said rectangular shaped section on the other end of said pin forming saiD first-named stop on said pin.
 32. The combination of claim 28 in which said stopper is hinged to said stopper seat.
 33. An article as recited in claim 28 in which said hinge is a flexible hinge.
 34. The combination of claim 24 in which said stopper seat has a skirt depending therefrom and sized to engage the exterior of the mouth of a bottle.
 35. The combination of claim 34 in which said skirt has a pair of annular grooves formed in and encircling the interior thereof to engage corresponding ridges upon the exterior of the mouth of a bottle.
 36. The combination of claim 24 in which said stopper seat is at the mouth of a bottle.
 37. In combination: a container having a stopper seat; a stopper, sized to fit into and conform to said stopper seat, including at least one slide channel formed in and directed across said stopper; at least one recess in said stopper seat, aligned with said slide channels; and at least one pin, each slidable in said recesses and one of said slide channels to lock said stopper into said seat.
 38. The combination of claim 37 in which said pins are equal in number to said recesses. 